Don't use any. Car keys stay where they belong, in the ignition, house keys I have not seen for 12 years.
I do not carry any keys, at all, period. 14 years, no one has ever robbed me, stolen my car etc.
Stop living the media-fear world and grow up. Keys are stupid, if someone came and broke very window in my house,
no one would hear, they could then load whatever they wanted into a van, no one would see and be off, all while making a huge
racket and a lot of noise.
Same with cars, nobody steals cars, if they do, they get caught and busted quick.
Stop living in fear.